Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. Pyplot is a state-based interface to a Matplotlib module which provides a MATLAB-like interface. There are various plots which can be used in Pyplot are Line Plot, Contour, Histogram, Scatter, 3D Plot, etc.
matplotlib.pyplot.quiverkey() Function
The quiverkey() function in pyplot module of matplotlib library is used to add a key to a quiver plot.
Syntax: matplotlib.pyplot.quiverkey(Q, X, Y, U, label, **kw)
Parameters: This method accept the following parameters that are described below:
- Q: This parameter is the Quiver instance returned by a call to quiver.
- X, Y : These parameter are the x and y coordinates of the location of the key.
- U: This parameter is the length of the key.
- label: This parameter is a string with the length and units of the key.
- angles : This parameter is the angle of the arrows.
- color : This parameter is the overrides face and edge colors from Q.
- labelpos : This parameter is used to position the label above, below, to the right, to the left of the arrow.
- labelsep: This parameter is the distance in inches between the arrow and the label.
- labelcolor: This defaults to default Text color.
- fontproperties: This parameter is the dictionary with keyword arguments accepted by the FontProperties initializer: family, style, variant, size, weight.
Below examples illustrate the matplotlib.pyplot.quiverkey() function in matplotlib.axes:
Example 1:
# Implementation of matplotlib function import matplotlib.pyplot as plt import numpy as np X = np.arange(-20, 20, 0.5) Y = np.arange(-20, 20, 0.5) U, V = np.meshgrid(X, Y) q = plt.quiver(X, Y, U, V) plt.quiverkey(q, X = 0.5, Y = 0.5, U = 500, label ='Quiver key') plt.title('matplotlib.pyplot.quiverkey() Example') plt.show() |
Output:
Example 2:
# Implementation of matplotlib function import matplotlib.pyplot as plt import numpy as np X, Y = np.meshgrid(np.arange(0, 2 * np.pi, .2), np.arange(0, 2 * np.pi, .2)) U = np.cos(X**2) V = np.sin(Y**2) C = U**2 + V**2 Q = plt.quiver(X, Y, U, V, C, units ='width') plt.quiverkey(Q, 0.4, 0.9, 1, r'val = $Cos(x ^ 2)^2 + Sin(x ^ 2)^2$', labelpos ='E', coordinates ='figure') plt.title('matplotlib.pyplot.quiverkey() Example\n', fontsize = 14, fontweight ='bold') plt.show() |
Output:
